A

Abandonment: Intentional, prolonged nonuse of a water right, resulting in its loss.  

Acre-feet: a measurement based on the volume of water that will cover 1 acre to a depth of 1 foot. 

Adjudication: The judicial determination of water rights that existed prior to July 1, 1973; decreeing the quantity and priority date of all pre-1973 water rights in a basin, including the total or partial abandonment of existing water rights occurring at any time before the entry of the Final Decree. 

Appropriate: To capture, impound, or divert water from its natural course and apply toward a beneficial use. 

B

Basin: The area drained by a river and its tributaries; a watershed. 

Beneficial use: A use of water recognized as beneficial prior to July 1, 1973, and used for the benefit of the appropriator, other persons, or the public and may include but not be limited to irrigation, stock, domestic, fish and wildlife, industrial, mining, municipal, power generation, and recreational uses. 

C

Claim: An assertion that a water right exists, usually occurring during the adjudication process. 

Claim examination: A review by the Department of Natural Resources and Conservation to determine if the claim is complete, accurate, and reasonable; examination may result in the addition of issue remarks.  

Compact: A legal agreement between Montana and a federal agency or an Indian tribe determining the quantification of federally or tribally claimed water rights. 

Cubic feet per second (cfs): A measurement based on a rate of water flow that will supply 1 cubic foot of water in 1 second. 

D

Decree abstract: The abstract that is part of Water Court issued decree. The decree abstract contains the original or amended claim information, changes authorized by the Water Right Adjudication Rules or the Water Court, Water Court ordered data, and remarks. 

Decreed water right: A water right issued by the court upon adjudication of a stream. 

Department of Natural Resources and Conservation (DNRC): State of Montana executive branch agency tasked with overseeing the post-1973 administration of water rights, including ownership updates or water right transfers. DNRC assists the Water Court via claim examinations and the issuance of basin summary reports, among other directives.  

E

Existing right: A Montana water right originating on or before July 1, 1973, that is subject to adjudication; must be associated with a statement of claim unless an exempt use recognized in the Montana Water Use Act.  

F

Final Decree: The final Water Court determination of existing water rights within a basin or subbasin, as described in §85-2-234, MCA. 

Flow rate: The rate at which water is diverted from a source; typically measured in gallons per minute (gpm), cubic feet per second (cfs), or miner’s inches.  

I

Instream flow: Water left in a stream for nonconsumptive uses such as preservation of fish or wildlife habitat. 

Interlocutory Decree: A Water Court decree limited to exempt (domestic and stock) and late-filed (1982-1996) claims that were not included in a previous decree for the basin; a judgment that does not settle all issues in a case. 

Issue remark: See “Remarks” 

J

Junior appropriator: A secondary user on a watercourse who holds a water right inferior to previous (senior) users. 

M

Miner’s inches: By Montana law, 1 cfs is approximately equal to 40 miner’s inches. 

Montana Code Annotated (MCA): Montana’s laws and statutes; Title 85, Chapter 2, MCA is known as the Montan Water Use Act.

Montana Water Court: A specialized court that has exclusive jurisdiction over the adjudication of pre-1973 water right claims.   

O

Objection: A formal objection to certain elements of a statement of claim submitted to the Water Court during an appointed period in the adjudication process prior to the issuance of a Final Decree. 

P

Preliminary Decree: The preliminary Water Court determination of existing water rights within a basin or subbasin as described in §85-2-231, MCA, which precedes the Final Decree. 

Priority date: The official date of an appropriation, generally the date of established intent; used in determining seniority among water users. 

R

Reexamination Decree: Water Court decree containing a limited examination of water right claims in Temporary Preliminary and Preliminary Decrees generally issued before 1997.  

Remarks: Statements added to an abstract by the DNRC or the Water Court to limit or define a water right, to explain unique aspects of the water right, and to identify potential factual and/or legal issues. Remarks that limit, define, or explain unique aspects of a claim are “clarifying” or informational remarks. Remarks that identify potential factual or legal issues are “issue” remarks which are underlined on an abstract. All issue remarks must be finally resolved before a Final Decree can be issued.  

S

Senior appropriator: An original user on a watercourse who holds a water right superior to all subsequent (junior) users. 

Statement of Claim: A sworn statement of an existing water right, as defined in §85-2-224, MCA, filed with the DNRC upon order of the Montana Supreme Court. 

Summary Report: Report to the Water Court that contains the DNRC examination findings for a given basin and serves as the basis for a Water Court decree.  

T

Temporary preliminary decree: A Water Court decree, prior to the issuance of the preliminary decree, as necessary for the orderly administration of existing water rights pursuant to §85-2-231, MCA. Temporary preliminary decrees are typically issued in basins with unresolved federal reserved and/or compact rights, including tribal compacts. 

V

Volume: Amount of water diverted over a specific period of time. 

W

Water master: An attorney versed in water law who serves at the discretion of the Water Court.